The present invention relates to a seat pillar lock device for an exercising machine which allows the seat pillar to be conveniently adjusted to any of a series of elevations.
A variety of exercising machines have been disclosed, and have appeared on the market. An exercising machine may have a seat for the user to sit when the user is operating the exercising machine. In order to fit different users, the seat of an exercising machine is commonly made adjustable so that it can be adjusted to the desired elevation according to individual's requirement. FIGS. 1 and 2 show a seat pillar lock device according to the prior art, which is generally comprised of a nut 3' fastened to the seat tube 2', a steel ball 4' and a spring 5' received in the nut 3', a socket 6' fastened to the nut 3' by a screw joint, a knob 8', and a screw rod 7' threaded into the inner thread on the socket 6' and having one end supported on the spring 5' and stopped against the steel ball 4' and an opposite end extended out of the socket 6' and connected to the knob 8' by a screw 9'. When the knob 8' is turned in one direction to turn the screw rod 7' inwards, the steel ball 4' is squeezed into either of a series of vertically spaced recessed hole on the seat pillar 1' to lock the seat pillar 1' in position. This structure of seat pillar lock device is complicated to manufacture because the screw rod and the knob must be processed with a respective hole for fastening, and the front end of the screw rod 7' must be properly made to fit the steel ball 4'. Furthermore, simply engaging the steel ball 4' into either recessed hole on the seat pillar 1' cannot firmly stop the seat pillar 1' from being oscillated, and the seat pillar 1' may slip in the seat tube 2' which can cause injury to a user.